Dry Climate Research Articles

Geochemical characteristics of the upper carboniferous source rocks in a terrestrial-marine transitional environment from the shuangjingzi area, Junggar Basin: Insights into palaeoenvironment, palaeoclimate, and palaeovegetation

The Upper Carboniferous organic-rich sediments record the depositional transition from terrestrial to marine environment across the Shiqiantan Formation-Batamayineishan Formation boundary. The geochemical characteristics of source rocks deposited in such terrestrial-marine transitional environments are not clear. The Late Carboniferous palaeovegetation, palaeoclimate and palaeoredox conditions are comprehensively reconstructed by combining organic petrology, molecular biomarkers, stable carbon isotopes and elemental composition. The molecular composition characteristics and stable carbon isotope compositions suggest a major terrestrial organic matter input with a lesser contribution of algae. Oxic to suboxic conditions for the Late Carboniferous sediments can be inferred from the elemental composition and biomarker proxies. A wet, cool, and seasonal dry climate during the Late Carboniferous can be deduced based on biomarkers, macerals, and spore and pollen records. The Late Carboniferous period is characterized by the enhanced burial of terrestrial organic carbon, coinciding approximately with the intensification of the Late Paleozoic Ice Age. The expansion of terrestrial floras in the Late Carboniferous is likely associated with the Late Paleozoic Ice Age.

Woody encroachment: social-ecological impacts and sustainable management.

Woody plants are encroaching across terrestrial ecosystems globally, and this has dramatic effects on how these systems function and the livelihoods of producers who rely on the land to support livestock production. Consequently, the removal of woody plants is promoted widely in the belief that it will reinstate former grasslands or open savanna. Despite this popular management approach to encroachment, we still have a relatively poor understanding of the effects of removal on society, and of alternative management practices that could balance the competing needs of pastoral production, biodiversity conservation and cultural values. This information is essential for maintaining both ecological and societal benefits in encroached systems under predicted future climate changes. In this review, we provide a comprehensive synthesis of the social-ecological perspectives of woody encroachment based on recent studies and global meta-analyses by assessing the ecological impacts of encroachment and its effects on sustainable development goals (SDGs) when woody plants are retained and when they are removed. We propose a working definition of woody encroachment based on species- and community-level characteristics; such a definition is needed to evaluate accurately the effects of encroachment. We show that encroachment is a natural process of succession rather than a sign of degradation, with encroachment resulting in an overall 8% increase in ecosystem multifunctionality. Removing woody plants can increase herbaceous plant richness, biomass and cover, but at the expense of biocrust cover. The effectiveness of woody plant removal depends on plant identity, and where, when and how they are removed. Under current management practices, either removal or retention of woody plants can induce trade-offs among ecosystem services, with no management practice maximising all SDGs [e.g. SDG2 (end hunger), SDG13 (climate change), SDG 15 (combat desertification)]. Given that encroachment of woody plants is likely to increase under future predicted hotter and drier climates, alternative management options such as carbon farming and ecotourism could be effective land uses for areas affected by encroachment.

CONDITIONS OF THE OAK FORESTS GROWTH AND CULTIVATION ON THE TOP SURFACES AND SLOPES OF THE NEAR-VOLGA AND ERGENI UPLANDS AND THE PLAINS OF THE SAL-MANYCH INTERFLUVE

Planted oak forests in the south of European Russia are of great conservation and economic importance. The widespread practice of their creation in dry steppes and semideserts dates back to the 1950-1970s and allows to form oak (Quercus robur L.) plantations with longevity up to 40-60 years. The aim of the study is to investigate the growth features of oak trees under different soil-climatic and biocenotic conditions and to suggest methods to increase their longevity.The research was carried out in 2011-2016 in the south of the Near-Volga Upland, the northern part of the Ergeni Upland and lowland plains of the Sal-Manych interfluve at 28 temporary sample plots using common methods of forest inventory and regression data analysis.It has been established that the viability of oak is limited by unfavorable topographic position of plantations, increased climate dryness (HC 0,4-0,6), high content of soil carbonates and shallow-lying horizon of their accumulation, as well as the presence of shrub layer and other competitors for moisture. Under these conditions, afforestation of depressions on the plains and shady slopes with pure plantations of oak and other species without shrubs should gain advantage. The methods of their creation should be modified depending on the topographic position of particular forest area and the climate dryness.So, the main soil cultivation in depressions could last 1-2 years, applying the system of black fallow with plantation plowing. It is advisable to keep 3,5-4,0-meter row spacing, frequent tending, and intensive clearing of young tree stands. Maturer plantations need careful sanitary-selective cuttings, mainly the low-type ones, and preservation of high canopy density. Poor water availability and deterioration of plantations should be prevented by construction of dams.Reclamation plantations of low marketability are created on flat areas after 2-3 years of deeper basic tillage. The carbonate horizon should be loosened and a large moisture reserve is needed. Row spacing of 2,5-3,0 meters is reasonable, accelerating the canopy closure. The area of tree nutrition is expanded by low-intensive uniformly selective cuttings, forming more open stands. The longevity of oak in already existing plantations could be increased by eliminating its competitors, such as living ground cover, shrubs and associated species.

Increases and decreases in soil moisture in water‐limited plant communities cause asymmetrical responses in biomass but not in diversity

AbstractAimsChanges in precipitation patterns, such as the predicted increases in the frequency of climatic extremes, are likely to alter plant communities, but whether responses to drought or to wetter conditions respectively cause consistent, opposite responses is debated. Here, we assessed the response in biomass production and species diversity of water‐limited plant communities to the direction (increase or decrease) and magnitude (micro‐ and macro‐climatic effects) of changes in soil moisture.LocationWe reciprocally translocated soils containing seed banks from two climates (semi‐arid and mediterranean) at a micro‐climatic (opposite slopes) and a macro‐climatic scale (between climates) in Chile.ResultsBiomass production for the soils that were translocated from wetter to drier climates was unrelated to the available soil moisture. The lowest biomass was produced in the wettest climate on the wet slope. Biomass production increased after a translocation to the drier climate (representing the largest change in climate). Nonetheless, the highest overall biomass for the wet to dry translocation was produced on the mediterranean dry slope with intermediate soil moisture. However, on the same mediterranean dry slope, biomass was almost zero for soil translocated the other way round (from drier to wetter). Diversity after 24 months was unaffected by micro‐climatic change, but soils transplanted toward the drier climate yielded a plant community with increased diversity.ConclusionOur results showed direction and magnitude of climate change but also the response factor that is studied matters to detect direction‐dependent responses; i.e., species richness had a linear and reversible response. However, the response of biomass depended on the origin of the transplanted material (soil and plant community), indicating history dependence (hysteresis). This emphasizes that responses to unidirectional climate manipulation experiments may not be able to capture the entire nature of the response of plant communities to climate change.

Energy consumption and thermal comfort of rock-cut and modern buildings

Energy consumption in the building sector justifies the necessity of knowing the thermal comfort perception of vernacular and modern architectural types, based on which a correct recognition was reached for the design of buildings suitable for the climatic conditions of each region. It should be determined that the different types of modern and traditional architecture are in the comfort level in harsh hot climate conditions and how much energy they consume to reach the comfort level. Despite consideration of energy consumption and thermal comfort in different buildings in Iran, there is no clear framework for evaluating these two parameters in different buildings and comparing them. This research aims to compare the indoor thermal comfort levels of vernacular architectural buildings and modern buildings in Iran's semi-hot and dry climate at the peak of summer heat and determine their energy consumption to reach the comfort level. This study has been accomplished by collecting field data, examining the indoor predicted mean vote (PMV) index of the buildings, and comparing them. It was found that rock-cut architecture buildings are in better thermal comfort conditions without energy consumption due to the use of groundmass temperature and low heat exchanges between the indoors and outdoors because of the thermal phase of the materials and the thickness of its layers. The indoor PMV average of rock-cut buildings in summer is −0.61; in modern buildings, it is 0.77, while these two building complexes are in the same climate and close. Also, the energy consumption to reach the comfort level in rock-cut buildings is zero, while modern buildings consume an average of 7.7 kW of electricity daily. The research results will lead to recognizing and modeling the climate design of vernacular architecture, which can be used in today's architecture to reduce energy consumption.

Late quaternary palaeoclimates in the lower Kürtün valley (Samsun, Northern Türkiye) through multi-proxy analysis of palaeosoil sediments

Palaeoclimatic and palaeoenvironmental proxy data are presented for the Late Quaternary based on mineralogical, geochemical and palynological analysis of a palaeosoil-sediment section in the lower Kürtün Valley (Samsun region, Northern Türkiye). The geochronology along the section is established based on OSL and radiocarbon dating. The base of the palaeosoil-sediment section consists of a palaeo-terrace fill of the Kürtün Creek dated to 108 ± 9 ka, corresponding to the last interglacial period (MIS5c). After this warm and humid period, the last ice age began. Sea level dropped and the Kürtün Stream deepened its bed. Fluvial terrace deposits were covered with colluvial materials and a palaeosoil sequence formed. The bottommost part of the palaeosoil formation carries the fingerprints of a dry climate of 68 ± 9 ka ago (MIS4). The middle part of the section coincides with MIS2 (28,959 cal BP) and is characterized by humid conditions with arid pulses accompanied by the occurrences of calcrete nodules. The palaeosoil-sediment section ends with the records of MIS1 (8381 cal BP), corresponding to warmer and more humid conditions. This study emphasizes the importance of palaeosoil-calcrete formation in the lower Kürtün Valley for explaining climate changes from MIS5c to MIS1. The results are compatible with studies conducted in the Eastern Mediterranean. High-resolution multi-proxy studies are recommended to better understand the connection between local climates and global climate phenomena in the Late Quaternary.

Atrium Design in Hot and Dry Climates: Understanding the Influence of Achitectural Form Variation on Indoor Thermal Conditions

The atrium is becoming more prevalent in desert regions as a key architectural and functional element in the urbanlandscape. In southern Algerian cities, we are observing an increasing integration of centralized atriums in publicbuildings. However, this integration may have an impact on the indoor environmental conditions of the buildings. Thisstudy investigates the influence of architectural aspects on the indoor thermal behavior of an existing centralized andenclosed atrium in the hot and dry climate of Laghouat. The study analyzes the influence of tow parameters, namelyheight and glazed area ratio, during summer season. The EDSL-Tas software for dynamic thermal simulation modelingwas used. The results revealed that the vertical temperature distribution in the atrium varies depending on its design,as a result of incoming solar radiation.

SPRING WHEAT IN THE DRY CLIMATE OF THE LOWER VOLGA REGION OF RUSSIA

Background. The growing of spring wheat in arid conditions is a difficult task because the biological characteristics of the crop and its demands on moisture reserves. The need for sowing spring wheat in the spring is dictated by the possible death of winter grains in winter. Purpose. To determine the most adaptive varieties of spring wheat with high yield and good quality for cultivation in the dry climate of the Lower Volga region of Russia. Methods. To achieve this goal, an environmental test of spring wheat varieties was carried out by us; the harvest results were processed by analysis of variance. To characterize weather conditions, the hydrothermal coefficient was calculated according to T.G. Selyaninov. An analysis of the ability of varieties to adapt to local climatic conditions was carried out using the coefficient of adaptability, stress resistance and compensatory ability of varieties. The graph was constructed and statistical data processing was carried out in Microsoft Excel 2008. Result. As a result of the research work, it was established that on average over three years of research, the highest yield of spring wheat was in the following varieties: Saratovskaya 73 -1.65 t/ha, Kamyshinskaya 3 - 1.32 t/ha, Bezenchukskaya 205 - 1, 4 t/ha. Processing of spring wheat harvest data are used by dispersion analysis made it possible to determine that the gross harvest of the crop is largely influenced by meteorological conditions, up to 42.0%, the choice of variety is about 19.7%, and agrotechnological and other environmental factors are 38.2%. It can be noted that spring soft wheat in the conditions of the Lower Volga region is capable of producing grain yields of good quality with large grains from 31.2 to 36.4 g of 1000 grains. Analysis of indicators of the level of resistance to drought conditions shows that the most stress-resistant varieties are: Zinaida - 0.06 t/ha, Kamyshinskaya 3 - 0.24 t/ha, Albidum 188 - 0.24. The varieties that have the highest genetic flexibility in the conditions of the Lower Volga region are: Saratovskaya 73 - 1.72 t/ha, Bezenchukskaya 205 - 1.5 t/ha and Kamyshinskaya 3 - 1.32 t/ha. The spring wheat varieties Bezenchukskaya 205 have the highest responsiveness to changes in crop growth conditions - 0.12, Dobrynya is in second place - 0.14, Albidum is in third place, Kamyshinskaya 3 - 0.15. The adaptability coefficient is higher than 1 in the varieties Albidum 188, Kamyshinskaya 3, Saratovskaya 73, Prokhorovka, Zinaida. Conclusion. The varieties Saratovskaya 73 and Kamyshinskaya 3 are distinguished by yield, stress tolerance, genetic adaptability to dry climate.

Limited waterpower contributed to rise of steam power in British "Cottonopolis".

The Industrial Revolution precipitated a pivotal shift from waterpower to coal-fueled steam power in British textile mills. Although it is now widely accepted that steam was chosen to power factories despite the availability of sufficient waterpower resources across most of Britain, the location and suitability of that waterpower during the early 19th century remain underexplored. Here, we employ quantitative fluvial geomorphology alongside historical climate data, factory records, and a catalog of over 26,000 mill sites to reveal that waterpower was abundant for most of early 19th century Britain, except in the central hub of British cotton production: Greater Manchester in the Mersey Basin. Our findings show that surging factory mechanization and overcrowding on key waterways in the Mersey Basin compounded waterpower scarcity arising from a drier 19th century climate. Widespread adoption of coal-fueled steam engines in certain key industrial centers of Britain was a strategy aimed at ameliorating some of the reduced reliability of waterpower. The fact that steam engines were frequently used in water-powered factories in many industrial regions until the third quarter of the 19th century to recirculate water to provide that power, or as a power supplement when waterpower availability was restricted, adds further weight to our argument. Rapid adoption of coal-powered steam engines reshaped the social and structural landscape of industrial work, firmly established Britain's prominence as an industrial powerhouse, and had lasting global industrial and environmental impacts.

Fruit quality, antioxidant, and mineral attributes of pomegranate cv. Ghojagh, influenced by shading and spray applications of potassium sulfate and sodium silicate

Pomegranate (Punica granatum L.) fruit quality depends on many traits including visual, biochemical and mineral characteristics. One of the negative traits is aril whitening (AW) which is a frequently observed disorder in hot and dry climates, that leads to decline in desirable fruit quality. Color, antioxidant, and mineral contents of the arils are of prime importance as quality traits. Therefore, this study aims to investigate the effect of shading and foliar minerals on fruit quality during the fruit development stages of pomegranate. Treatments included shaded (50% green net) and unshaded trees and foliar application of trees with potassium sulfate (K, 1% and 2%) or sodium silicate (Si, 0.05, 0.1 and 0.15%) during two growing seasons. Results showed that the severity of AW at harvest decreased significantly when trees were covered with shading compared to control. The color values of L* and ⁰hue for arils were lower in fruits grown under shading conditions indicating darker red arils. Shading significantly reduced chilling injury in cold storage compared to open field fruits. Shading and Si 0.15% increased superoxide dismutase, and catalase enzymes activity while decreased Polyphenol oxidase and peroxidase. Covering trees with shading and Si 0.15% spray resulted in the highest total anthocyanin, antioxidant activity, and total phenolics content in the arils. Shading as well as Si 0.15% increased macronutrients content of the arils. The study concluded that covering pomegranate trees and spraying with Si in hot climate reduced AW, increased antioxidant traits, and led to higher fruit quality.

Microclimatic models and their implications on the energy requirements of buildings in warm dry urban areas

Understanding the parameters that amplify or mitigate temperature increases in the built environment is crucial to reducing the energy demand of buildings and achieving urban resilience. This research examines how microclimate scenarios can affect building energy performance forecasts in cities with temperate and dry climates. The aim is to calculate the variation in building energy requirements resulting from using different weather files and urban parameters using the UBEM tool. To achieve this, UWG and Energy Plus software were used to create urban and building models. The study analysed four microclimatic scenarios in the city of Mendoza, Argentina. The scenarios used as a weather file input the annual format of a specific year (AMY files) or long-term (TMY file), whilst also considering the specific urban parameters of the assessed area. The study found that an incorrect weather file can cause a 36% error in energy usage assessments for cooling buildings during summer months. The contribution of this study is the development of a methodology for obtaining a weather file that accurately reflects the microclimate characteristics of the urban area of interest.

Climate variability in northern Africa during the late Holocene: A multiproxy perspective from El-Beida Lake (Wadi El-Natrun, Egypt)

North Africa is a key region hosting ca. 230 million people that are dependent on climate to maintain their subsistence through agriculture. Because of the current global changes, understanding the mechanisms behind the climate variations that occurred in this region is extremely important. To contribute to a more accurate modelling projection, we reconstructed the paleoclimatic and paleoenvironmental variations from the Meghalayan (∼1,500 ka) to recent using palynological and geochemical data from a sediment core from El-Beida Lake (Wadi El-Natrun area, north Western Desert of Egypt). North Africa underwent significant shifts in climatic conditions forced by different drivers since the Roman Warm Period (RWP) until recent. Our sediment core record indicates that this region experienced a persistent dry and warm climate during the RWP until the first half of the Medieval Climate Anomaly (MCA). The positive North Atlantic Oscillation was the main driver for controlling the precipitation pattern and pushing the precipitation towards central and north Europe and favoring the dry climate in North Africa during the RWP. The dry and slightly cold conditions in the study area during the Dark Age Cold Period (DACP) can be ascribed to the coupling between the more southward position of the Azores Front and the weak Atlantic Meridional Overturning Circulation. Northern Africa showed variable climatic conditions during the Medieval Climate Anomaly (MCA) due to the complicated thermohaline circulation of the Mediterranean Sea. During this time, the Eastern Mediterranean experienced a cold or partially cold MCA that may be extended to the present study area. An abrupt change to humid and cold climatic conditions occurred in northern Africa during the Little Ice Age (LIA) due to large-scale processes like the ENSO and NAO. The SST warming of the North Tropical Atlantic (NTA), significantly influenced by ENSO, causes the position of the Atlantic ITCZ to be shifted northward affecting precipitation in Africa.

Thermal conditions and daylight availability in different zones of courtyard buildings; a study in Iran

ABSTRACT Passive design strategies enhance indoor thermal comfort and reduce energy consumption in buildings located in hot climates. Thus, exploring the various zones of a house’s yard can yield valuable insights for devising a plan that achieves high energy and lighting efficiency. This study examines the climate-responsive design strategies of 20 traditional courtyard buildings in Birjand’s hot and dry climate. These courtyard houses informed modelling a new hypothetical house in DesignBuilder. Two main orientations (45° = NE–SW, and 315° = NW–SE) were used for comparing their impact on indoor air temperature, solar gain and daylight factor across various courtyard zones. The findings indicate that during winter, the interiors of courtyard houses maintain a temperature higher than the exterior, while in summer, they remain cooler than outside conditions. Concerning the influence of orientation on indoor climates, the NE–SW orientation yielded the greatest solar gains for windows in the northern and western zones. Conversely, in the NW–SE orientation, the most substantial solar gains were recorded for windows in the northern and eastern zones. Additionally, the study noted a marginal variation in the daylight factor across different zones of the courtyard houses when comparing the two orientations.

Quaternary geomorphological dynamics of colluvial deposits from silicophytoliths and soil micromorphology, Araripe plateau, northeast of Brazil

Quaternary geomorphological dynamics in the lowland tropics of South America can be described from the stratigraphy of hillslope colluvium and alluvial deposits. The analysis of sediments through the identification of depositional microfeatures and biomineralized microfossils, combined with their absolute dating by optically stimulated luminescence (OSL), allow the reconstruction of paleoenvironmental conditions. The objective of this work was to investigate the dynamics of depositional processes leading to colluvial deposition in the Araripe Plateau, Northeastern Brazil, from the analysis of stratigraphic sections, using phytoliths as indicators of paleovegetation and sediment micromorphology in the identification of depositional processes. The correlation of sediments ages, ranging from the OS3 to the OS2 (Last Glacial Maximum) with phytophysiognomy indices indicated the contribution and deposition of phytoliths from an arboreal/shrubby vegetation, replaced on the surface by grass vegetation. Periods of drier climates were correlated with LGM ages, with more open vegetation composed of grasses, in synchronously with less intense geomorphological events. The micromorphological analysis revealed that the characteristics of the deposits reflect more the action of depositional processes than pedogenetic ones. The correlation of phytolithic indices with micromorphology corroborated the environmental and geomorphological dynamics of the periods dated in the stratigraphic sections.

Electroluminescence and infrared imaging of fielded photovoltaic modules: A complementary analysis of series resistance-related defects

Fielded photovoltaic (PV) modules often exhibit series resistance-related defects, mainly due to solder bond degradation and metallization corrosion. To quantitatively analyze the series resistance increase in fielded modules, we conducted a detailed investigation on two sets of modules, employing two complementary techniques, electroluminescence (EL) and infrared (IR) imaging. The dependence of EL image characteristics on module temperature, as revealed in IR images, was a key focus of this study. The first and second sets of modules were exposed in Florida (hot and humid climate) and Arizona (hot and dry climate) over 10 years and 18 years, respectively. The resistive defect patterns obtained using EL and IR images showed a closer correlation for the Florida modules compared to the Arizona modules as the Florida modules primarily experience solder bond degradation. EL and IR images were acquired at five current injection levels (i.e., 0.1, 0.3, 0.5, 0.7, 1.0 x short circuit current) and two exposure times (i.e., 60 s and 300 s) and used to develop and report a new curve fitting method for estimating the external series resistance. The results indicate that inaccurate temperature determinations from IR images can lead to underestimations (up to 23 %) in EL-based external series resistance estimates. For the most accurate series resistance estimation, especially in modules with severe thermal defects and series resistance deterioration, the study recommends obtaining EL and IR images within 60 s of the current injection time. This study also reports a Monte Carlo simulation assessing the impact of EL and IR characteristics on the accuracy of external series resistance estimations.

The Effect of Fertilizers and Growth Regulators on the Productivity of Safflower (Carthamus tinctorius L.) in the Dry Climate of Russia

Background: Safflower is an oilseed crop capable of forming seeds in extreme conditions, so it can be used as an alternative to sunflower, because their growing technologies are similar. Increasing the yield of safflower seeds can be achieved intensively using agrochemicals. The proposed research results provide information on the use of mineral, micro fertilizers and growth regulators. Methods: Research was carried out in the dry steppe zone of chestnut soils. In the spirit-factor experiment, which was located on a field with an area of 300 m2, in triplicate, using two sorts of safflower. Mineral fertilizers were applied to the soil during sowing and by foliar treatment during the “budding” phase. The obtained yield results were processed by analysis of variance. Result: As a result of the research, elite safflower seeds were obtained using one of the experimental options Ultamag Bor 30 g + Biostim Growth 30 g/10 liters of water of the Alexandrite variety with a yield of 1.8 t/ha with the highest profitability of their production of 414.2%. Analysis of variance of the yield data from the experiment showed that 87% of the yield of safflower seeds depended on the use of mineral fertilizers, 0.62% on the plant variety and agro technical measures for growing safflower plants-11.8%.

Urban Stormwater Phosphorus Export Control: Comparing Traditional and Low-impact Development Best Management Practices.

Data from the International Stormwater Best Management Practices (BMP) Database were used to compare the phosphorus (P) control performance of six categories of stormwater BMPs representing traditional systems (stormwater pond, wetland basin, and detention basin) and low-impact development (LID) systems (bioretention cell, grass swale, and grass strip). Machine learning (ML) models were trained to predict the reduction or enrichment factors of surface runoff concentrations and loadings of total P (TP) and soluble reactive P (SRP) for the different categories of BMP systems. Relative to traditional BMPs, LIDs generally enriched TP and SRP concentrations in stormwater surface outflow and yielded poorer P runoff load control. The SRP concentration reduction and enrichment factors of LIDs also tended to be more sensitive to variations in climate and watershed characteristics. That is, LIDs were more likely to enrich surface runoff SRP concentrations in drier climates, when inflow SRP concentrations were low, and for watersheds exhibiting high impervious land cover. Overall, our results imply that stormwater BMPs do not universally attenuate urban P export and that preferentially implementing LIDs over traditional BMPs may increase TP and SRP export to receiving freshwater bodies, hence magnifying eutrophication risks.

Leaf Architecture in the Morphological Diversity of the Genus Prosopis in the Semi-Desert Area of Northeastern Mexico

Mesquite (Prosopis spp.) is one of the main plant representatives in regions with a dry climate, and is a fundamental part of the flora of the Mexican arid, with an indisputable importance from ecological, economic and industrial points of view. However, the restrictive factors of dry climates, as well as genetic variability, are sources of the great diversity of mesquite, so its taxonomy is not yet well defined. The present study seeks to determine the diversity of mesquite in the Mexican semi-desert based on the morphometric characterization of its leaves. Methods: Different leaf parameters such as the number, length and width of the leaflets were recorded in 31 well-marked sites in the area, to obtain measures of central tendency and dispersion, and to determine the differences and similarities between the sites, as well as the groups of homogeneous and heterogeneous taxa. Results: Five taxa were identified, of which there were two varieties (Prosopis glandulosa var. glandulosa and Prosopis reptans var. cinerascens), a pure or typical species (Prosopis laevigata) and two hybrids (Prosopis glandulosa var. glandulosa x Prosopis laevigata and Prosopis laevigata x Prosopis glandulosa var. glandulosa). The discriminant analysis indicated that five variables presented the highest percentage of separation or best separated the taxa, so the study was based on the phenogram with the combination of these five variables: (a) length of middle leaflets, (b) length of upper leaflets, (c) spacing of middle leaflets, (d) length/width relationship of middle leaflets and (e) length/width relationship of middle leaflets. Conclusions: Both the traditional taxonomic classification and the cluster and discriminant analyses reflected the same taxa (Prosopis glandulosa var. glandulosa, Prosopis laevigata and Prosopis reptans var. cinerascens) and the existence of hybridization between Prosopis glandulosa var. glandulosa and Prosopis laevigata.

Eocene–Oligocene vegetation and climate changes in southeastern Brazil

The Eocene–Oligocene Transition (EOT) marks the onset of a major phase of global cooling with significant consequences to the vegetation worldwide. Here, we present palynological analyses from a site in southern São Paulo basin, southeastern Brazil (23.67°S; 46.58°W). An Oligocene age was constrained by the abundance of Dacrydiumites florinii and Podocarpidites spp., alongside the presence of taxa such as Cicatrocosisporites dorogensis and Polypodiisporites usmensis. Autochthonous elements including Paleoazolla, Corsinipollenites spp., Monoporopollenites annulatus, and Zygnemataceae algae spores are indicative of a low-energy freshwater depositional environment. In addition, we performed a comparison of Eocene and Oligocene temperature and precipitation estimates from records in southeastern Brazil using the weighted Mutual Climate Range approach. Results support global trends with a cooling of ca. 3–4 °C from the Eocene to the Oligocene accompanied by slightly drier regional conditions. Oligocene environmental changes drove a vegetation turnover by local extinction of warm-tropical taxa or a significant retreat of species unable to stand comparatively colder and drier climates under lower CO2atm concentrations. Our data are consistent with previous estimates and verify the impact of global cooling on the vegetation of mid-low latitudes of the Southern Hemisphere.

Analysis of Erosion and Sedimentation Rates on the Service Life of Telaga Lebur Dam

Dam is a civil construction structure in hydrology. The concept of a dam essentially provides a solution by serving as a water reserve, meaning that during the rainy season, water is collected in the dam reservoir, and during the dry season, the stored water can be used as needed. Dams are highly effective in addressing water scarcity issues, both for raw water supply and irrigation purposes. The purpose of building dams is to create a water supply system to supply water for village residents and for irrigation needs. Water availability in dry climate regions is generally limited. Climate change phenomena exacerbate water scarcity issues. As a precaution and mitigation measure against water scarcity, the Indonesian government is actively constructing dams across various provinces. Particularly in West Nusa Tenggara (NTB), a dry climate province facing challenges in water supply for households and irrigation, dam construction is essential. The level of total erosion hazard rate in the Telaga Lebur Dam Catchment Area is 5463.94 Ton/Ha/Year. 67.78% of the area of the Telaga Lebur Dam Catchment Area (11.23 km²) experiences erosion at a rate of 3703.5 Ton/Ha/Year, classified as very light erosion. 11.58% of the area of the Telaga Lebur Dam Catchment Area (25.90 km²) experiences erosion at a rate of 632.7 Ton/Ha/Year, classified as light erosion. 9.20% of the area of the Telaga Lebur Dam Catchment Area (20.58 km²) experiences erosion at a rate of 502.7 Ton/Ha/Year, classified as moderate erosion. 3.66% of the area of the Telaga Lebur Dam Catchment Area (8.19 km²) experiences erosion at a rate of 200 Ton/Ha/Year, classified as heavy erosion. 7.78% of the area of the Telaga Lebur Dam Catchment Area (17.41 km²) experiences erosion at a rate of 425.1 Ton/Ha/Year, classified as very heavy erosion. The total sediment yield in Telaga Lebur Dam is 16.619 m³/year. The reservoir's useful lifespan based on the analysis results is 11.44 years.